【作者】 曹胜利；

【导师】 程和法；

【作者基本信息】 合肥工业大学 ， 材料加工工程， 2009， 硕士

【摘要】 玻璃模具是玻璃制品成型的重要工装,模具材料质量的好坏直接影响玻璃模具的性能和使用寿命。目前,国内广泛使用的普通灰铸铁玻璃模具材料普遍存在着表面光洁差,使用寿命短的缺点。本文的目的是通过化学成分的控制和对工艺的调整,获得D型石墨,并对微观组织、力学性能、耐高温性能进行研究,以提高玻璃模具的使用寿命。(1)通过对C、Si和合金元素成分的选择和控制,研究了化学成分对D型石墨铸铁微观组织的影响。结果表明:C、Si是影响D型石墨形成的主要因素,Ti、Cr、Cu有利于促进D型石墨的形成;D型石墨铸铁玻璃模具适宜的化学成分范围为:3.2~3.5%C、2.2~3.0%Si、0.2%Ti、0.54~0.89%Mn、<0.05%S、<0.1%P、0.49~0.54%Cr、0.35~0.65%Cu;当含Ti量在0.1~0.3%之间变化时,随着含Ti量的增加,D型石墨增多。在此成分范围内获得的D型石墨铸铁的力学性能为:硬度HB范围为211~288,抗拉强度MPa范围为246~310。(2)通过采用浇注阶梯型试样和放置冷铁方法,使铸铁获得不同的冷却速度,研究冷却速度对D型石墨铸铁微观组织的影响。结果表明:随着冷却速度的增大,石墨形态由较粗大的片状石墨逐渐变成细小的点状石墨。在厚度为30mm试样的下方放置冷铁时,在距离冷铁25mm的铸铁组织中能够获得较细小的D型石墨组织。(3)对不同成分的D型石墨铸铁的高温抗氧化性进行了实验研究。在750℃下,将不同成分的D型石墨铸铁保温24小时,使其氧化增重,研究成分和组织对D型石墨抗氧化性能的影响。结果表明:含有Cr、Cu多元化合金的D型石墨铸铁有比普通灰铸铁高4~5倍的抗氧化性能。(4)对不同成分的D型石墨铸铁的高温抗热疲劳性进行实验研究。在800℃下,将不同成分的D型石墨铸铁加热到800℃,保温5分钟取出后,立即在冷水中激冷5秒,如此反复循环直至出现肉眼可见的裂纹为止。根据试样表面首次出现裂纹时的循环次数,研究成分和组织对D型石墨抗热疲劳性能的影响。结果表明:含有Cr、Cu多元化合金的D型石墨铸铁有比普通灰铸铁高5~6倍的抗热疲劳性能。(5)对试制的D型石墨铸铁玻璃模具还进行了工业性装机实验。装机实验结果表明:所研制的D型石墨铸铁玻璃模具具有良好的抗高温氧化性、抗生长变形和抗热疲劳等性能,使用寿命比普通灰铸铁增加5~6倍。更多还原

【Abstract】 Glass mold is a key processing tools in glass forming. The properties and service life of the glass mold are determined by the material of the mold. Presently, the common gray cast iron glass mold extensively used for glass production have deficiencies in poor surface and the short-life.The purpose of this paper is to obtain D-type graphite cast iron glass mold by controlling its chemical composition and adjusting the casting process. The microstructure, mechanical properties, high temperature performance are studied to improve the service life of glass molds.(1)By controlling and choosing C, Si and other alloying elements content. This paper has studied the impact of the chemical composition on the D-type graphite cast iron microstructure. The results indicate that the proper chemical composition range of D-type graphite cast iorn glass molds is 3.2 ~ 3.5% C, 2.2 ~ 3.0% Si, 0.2% Ti, 0.54 ~ 0.89% Mn, <0.05% S, <0.1% P, 0.49 ~ 0.54% Cr, 0.35 ~ 0.65% Cu. C and Si are the major factors in formation of D-type graphite in cast iorn. The element such as Ti, Cr, Cu can promote formation of D-type graphite in cast iron. The content of Ti of the cast iron is in the range of 0.1 ~ 0.3%. During the above chemical range, the mechanical properties such as hardness range of 211~288 HB, tensile strength range of 246 ~ 310 MPa is obtained for the D-type graphite cast iron can.(2)By using ladder-type specimen and placing cold iron, the cast irons can obtained different cooling rates. In this way, the effect of cooling rates on D-type graphite cast iron microstructure is studied. The results showed that large coarse graphite can be turned to punctuate and small graphite as increasing cooling rates .When a cold iron was placed under the bottom of the sample of 30mm thickness, the smaller D-type graphite can be obtained at the distance of 25mm in the cast iron.(3)The high-temperature oxidation resistance was studied on different composition of the D-type graphite cast iron. Different composition of the D-type graphite cast iron were heated to 750℃and kept for 24 hours, and the cast iron were oxidationed and its weight increased. In this way, the oxidation resistance of compositions and organizations on the D-type graphite can be studied. The results showed that the oxidation resistance of the D-type graphite cast iron containing Cr、Cu is 4 to 5 times higher than that of ordinary gray Cast Iron.(4)The thermal fatigue resistance were studied on different composition of the D-type graphite cast iron. In the thermal fatigue resistance, the D-type graphite cast iron was heated to 800℃and kept for 5 minutes, and then chilled in cold water for 5 seconds. This cycle was repeated until the crack was visible to the naked eye. According to the cycle times for creation of surface crack at the first time, the thermal fatigue resistance of compositions and organizations on the D-type graphite can be judged. The results showed that the D-type graphite cast iron containing Cr and Cu is 5 to 6 times of the ordinary Gray Cast Iron in the thermal fatigue resistance(5) The D-type graphite cast iron glass mold studied were also carried out on industrial installation .The results show that the D-type graphite cast iron glass molds studied has a good high temperature oxidation resistance, anti-growth deformation and thermal fatigue resistance, and has 5 to 6 times than ordinary Gray Cast Iron in service life .更多还原